Compounded hydrocarbon oils and addition agents therefor



Patented Oct. 6, 1953 UNITED STATES PATENT OFFICE 20 Claims.

This invention relates to addition agents for hydrocarbon lubricating oils in the nature of detergents and rust preventives. In particular, the invention relates to new salt compositions. More particularly, the invention is concerned with compounded hydrocarbon lubricating oils.

In the lubrication of internal combustion engines of all types, particularly when severe operating conditions are encountered, plain hydro carbon lubricating oils frequently prove unsatisfactory in service. Furthermore, many lubrieating oils which may be highly satisfactory for the lubrication of other mechanisms have been found wholly unsuitable for use as turbine oils.

Hydrocarbon lubricating oils are often objectionable because of deposition of sludge, carbonaceous materials, or varnish, and because they fall to prevent the formation of rust. Consequently, one or more addition agents are usually employed. For example, in order to counteract the tendency of lubricating oils to form deposits of gum and sludge, additives of a detergent na' ture are usually incorporated in such oils. To combat the formation of rust, rust-inhibiting agents are generally employed.

The lubricating compositions of the invention comprise a major amount of a hydrocarbon lubricating oil and a minor amount of a polyvalent metal salt of a monoamide of the class consisting of 2,5-endoethylene-A -cyclohexene-1,6- dlcarboxylic acid and alkyl-substituted 2 ,5-endo ethylene-o -cyclohexene1,6-dicarboxylic acids which contain not more than 4 alkyl groups each containing not more than 6 carbon atoms. The N-substituents of the monoamide are selected from the class of hydrogen and alkyl and allrenyl radicals and contain a total of 8 to 22 carbon atoms; i. e., where only one N-substituent is an allryl or alkenyl radical it contains 8 to 22 carbon atoms and if both N-substituents are radicals of this class, they contain a total of 8 to 22 carbon atoms. It has been found that polyvalent metal salts of this class confer valuable rust preventive and detergent properties to hydrocarbon lubricating oils in which they are incorporated. The "present invention includes the hydrocarbon lubricants containing a polyvalent metal salt of this class, the salts, and processes for making, the salts.

In accordance with the invention, the polyvat-lent metal salts are preferably prepared by first condensing cyclohexadiene-l,3 or an alkylsubstituted cyclohexadiene-1,3 which contains not more than 3 alkyl groups each of not more than 6 carbon atoms with an alpha-beta ethylenic dicarboxylic acid containing not more than 8 carbon atoms. The product resulting from this condensation is a 2,5-endoethylene-A -cyclo COMPOUNDED HYDROCARBON OILS AND ADDITION AGENTS Edward Mitchell, Pittsb THEREFOR No Drawing. Application June 7, 1951, Serial No. 230,421

2 hexene-LB-dicarboxylic acid or a corresponding amyl-substituted acid.

An alky1substitutecl acid prepared in this way from an alpha-beta ethylenic dicarboxylic acid having an alkyl group attached to the carbon atom to which the carboxyl group is attached, will also contain an alkyl group attached to a carbon atom to which a carboxyl group is attached. It will be understood that all of the compounds of this class which contain 4 alkyl groups must have one of these groups attached to a carbon atom to which a carboxyl group is attached. Moreover, such a carbon atom may contain an alkyl substituent in any case. For example, when cyclohexadiene1,3 is condensed with citraconic acid, the resulting cyclohexene dicarboxylic acid will contain one alkyl substituent and this a methyl group attached to a carbon atom to which a carboxyl group is also attached.

The acid formed as described is then reacted with a primary or a secondary amine containing a total of 8 to 22 carbon atoms under conventional amidating conditions to form the corresponding monoamide. The polyvalent metal salt of the monoamide is then prepared by reacting the monoamide with a suitable compound of the metal, ordinarily the metal oxide.

The reaction of the cyclohexadiene-L3 compound herein contemplated with alpha-beta ethylenic clicarboxylic acids. or the anhydrides, containing not more than 8 carbon atoms is essentially a Diels-Alder reaction. This reaction can conveniently be carried out at temperatures ranging from about F. to 375 F.; but I find it advantageous to carry out the reaction between about 300 F. and 340 F. However, once the reaction has started, it is self-sustaining. During the reaction, i. e.. when the ethylenic dicarboxylic acid and diene are reacted, the two compounds join together forming an endoethylene bridge. The product formed, depending upon the cyclohexadiene employed, is believed to be principally either 2:,5-endoethylene-A -cyclohexene-LG-dicarboxylic acid, or an alkyl-substituted dicarboxylic acid having not more than 4 alkyl groups each of not more than 6 carbon atoms. The alkyl groups may be any suitable lower alkyl groups such as methyl, ethyl, isopropyl, tertiary or secondary butyl, amyl and hexyl groups. The addition agents of the present invention are the polyvalent metal salts of the monoamides of said resulting acids.

As indicated previously, any alpha-beta ethylenlc dicarboxylic acid containing not more than 8 carbon atoms can be employed in accordance with this invention for reaction with the cyclohexadiene-LB compound. Suitable acids are maleic, citraconic, fumaric, glutaconic and their geometric isomers such as mesaconic acid and the like. It is understood, unless otherwise indicated, that acids and acid anhydrides are both included when reference is made to the acid or the anhydride since these two are equivalents.

It will be noted that when an acid, such as glutaconic acid, in which the two carboxyl groups are not both attached to the carbon atoms forming the ethylenic double bond is emloyed, the final cyclohexene dicarboxylic acid will be one in which a carboxyl group is linked to the cyclohexene ring through an alklene radical. Such compounds are equivalent to those in which both carboxyl groups are attached directly to carbon atoms of the cyclohexene ring, and are included when the 2,5-endoethylene-A -cyclohexene-1,6- dicarboxylic acids are referred to, unless otherwise indicated.

Preferred polyvalent metal salts in accordance with the invention are derivatives of alpha-terpinene, which itself can be formed from dipentone or A -menthadiene by heating the latter compound at a temperature adapted to rearrange the double bonds to a conjugated system, usually about 280 F. to the boiling point of dipentene; for example, about 280 F. to 375 F. When alpha-terpinene is condensed with maleic anhydride the resulting product is believed to be 2,5-

endoethylene 2 methyl-5-isopropyl-n -cyclohexene-1,6-dicarboxylic acid.

Examples of diene compounds adapted for use are cyclohexadiene-L3, 5-methyl cyclohexadiene- 1,3, the dimethyl cyclohexadienes such as 4,6-dimethyl cyclohexadiene-l,3, and 2,4 dimethyl cyclohexadiene-l,3, the trimethyl cyclohexadiones such as 4,5,5-trimethyl cyclohexadiene-l,3, the methyl isopropyl dienes such as alpha-terpinene, also, 1,5-dimethyl-3-ethyl cyclohexadiene- 1,3, 1 methyl-3-ethyl-4-isopropyl cyclohexadiene-l,3, l-methyl-fi-isobutyl cyclohexadiene-L3, and l-methyl-5-n-hexyl cyclohexadiene-1,3.

After the desired cyclohexadiene-1,3 is reacted with the unsaturated dicarboxylic acid, it is usually preferred to first prepare the monoamide by reacting the resulting product with a primary or secondary amine. The polyvalent metal salt of the moncamide is then subsequently prepared. However, an incompletely neutralized metal salt of the acid may be prepared first as desired, and the amide subsequently formed. By an incompletely neutralized salt I mean a half metal salt wherein there is a free carboxyl group in the dicarboxylic acid molecule. In preparing the amide, conventional amidation conditions can be employed; for example, the amine may be reacted at any temperature from room temperature to a temperature of about 250 F. with the product resulting from the cyclohexadiene-dicarboxylic acid reaction. Since the reaction proceeds more slowly at room temperature it is preferred to form the amide at an elevated temperature ranging from about 180 F. to about 200 F.

The amines which can be employed in the formation of the monoamides mentioned heretofore are primary alkyl or alkenyl amines having from 8 to 22 carbon atoms, and secondary alkyl and alkenyl amines having a total of from 8 to 22 carbon atoms. Examples of suitable amines are octyl amine, decyl amine, undecyl amine, dodecyl (lauryl) amine, tetradecyl amine, octadecyl amine, diamyl amine, dibutyl amine, octenyl amine, N-butyl-decenyl amine, decenyl amine, undecenyl amine, dodecenyl amine, tetradecenyl amine, hexadecenyl amine, and octadecenyl amine. Mixtures of amines such as are commercially available are desirable, for example mixtures of primary alkyl amines derived from fatty acids. These will be amines having from approximately 8 to 22 carbon atoms.

The polyvalent metal salts of the monoamides can be prepared directly, that is by neutralization or treatment with the metal oxide; or they can be prepared indirectly by double decomposition or metathesis. When the salt is prepared by neutralization, or when the metal oxide is employed, any temperature can be used ranging from room temperature to about 250 F. A preferred range, particularly when the metal oxide is used, is a temperature from about F. to about 220 F. Desirable metals employed in the salt-forming reaction are barium, magnesium, calcium, nickel, zinc, lead, copper, strontium,

aluminum, bismuth, iron, chromium and the like.

In preparing the metal salts of the present invention, equivalent amounts of the various reactants are generally used. Thus, about one mol of the diene, such as alpha-terpinene, is reacted with about one mol of the acid, for example, maleic anhydride, at a temperature from about 300 F. to 340 F. The monoamide is then prepared by using about one mol of the amine and a temperature from about 180 F. to 200 F. The monoamide so formed can then be neutralized with about one equivalent weight of a base such as barium hydroxide to form the metal salt,

When the unsaturated acid is contacted with the cyclohexadiene-1,3. some undesired polymer is normally formed. It is desirable to remove this polymer, which is conveniently accomplished by treatment of the final salts. The treatment preferably involves extraction with a solvent. The salts can be readily dissolved in common solvents such as benzene, Stoddard solvent, chloroform and light hydrocarbon oils. The solution is then filtered and, in the case of a voltatile solvent, heated to evaporate said solvent. Inasmuch as oil concentrates of the salts of the present invention are desirable for use, it is preferred to extract the salt using a light hydrocarbon oil.

The following examples illustrate the various methods of preparing my improvement agents and improved compositions containing the same.

EXAMPLE I A typical procedure for preparing salts in accordance with this invention was first to heat 38 parts by Weight of dipentene (technical, boiling 48 to 52 C. at 6 mm. pressure) at 300 F. for 30 minutes. At a. rate sufilcient ot maintain the temperature over 275 F., 26 parts by weight of maleic anhydride were added over a period of ten to thirty minutes, and the mixture was stirred at F. to 320 F. for about thirty minutes. The reaction was somewhat exothermic and maintained its own temperature for about ten to thirty minutes. The reaction product thus obtained was then cooled to approximately 200 F. and 60.5 parts by Weight of octadecyl amine were added at a rate such that the temperature did not exceed 220 F. This addition took about 15 minutes. After this addition the mixture was stirred at a temperature of 200 F. to 220 F. for fifteen minutes. Then, 6.35 parts by weight of magnesium oxide (about 25% excess) were slowly added and the mixture was stirred at a temperature of 200 F. to 220 F. for a period of from one to two hours. The final product was extracted with oneacugzcs third to one-hair gallon of "beams, filtered and the benzene was distilled ofl.

EXAMPLE II In this example 2'? parts by weight or alphaterpinene were heated to 'a temperatuirefrom 3-10 to 320 F. Then, 2 02 parts by'weight oi maleic anhydride were slowly added and the heating was continued at 310 F. to 320 F. for one hour. The reactants were then cooled to 200 F. and 46.4 parts by weight or octadecyl mine were added. the temperature being maintained at 200 F. tor thirty minutes. Then 5.20 parts by weight or magnesium oxide were added and the reaction mixture was agitated at a temperature of 210 F. to 215 F. for at least one hour. The magnesium salt thus formed was extracted with a volatile solvent, filtered and the solvent removed by distillation. The magnesium salt prepared in accordance with this invention was an amber tacky solid having the following properties:

Percent ash (oxide) 4tc5 Percent nitrogen 3.14 Sp. gr. @"77/60" F 0.9405 Viscosity Solid Neut. No 78.9 Sap. No 82.2 Acetyl N-o 83.7 Iodine No 28.7 'Melting point F 300 EXAMPLE III In this example 21.4 parts by weight of alphaterpinene were heated to a temperature from 310 F. to 320 F. Then, 15.4 parts by weight of maleic anhydride were slowly added and the heating was continued at 310 F. to 3 0 F. iorone hour. The reactants were then cooled to 200 F. and 35.8 parts by weight of octadecyl amine were added, the temperature being maintained at 200 F. for thirty minutes. Then 27.4 parts by weight of barium hydroxide were added and the reaction mixture was agitated at a temperature of 210 F. to 215 F. for at least one hour. The barium salt thus formed was extracted with a volatile solvent, filtered and the solvent removed by distillation. The barium salt prepared in accordance with this example was a red tacky solid. The percent ash. as the oxide, was 20.1.

EXAMPLE IV In this example 27.6 parts by weight 01 alphaterpinene were heated to a temperature from 310 to 320 F. Then, 2030- parts by weight or maleic anhydride were slowly added and the heating was continued at 310 F. to 320 F. for one hour. The reactants were then cooled to 200 F. and 46.3 parts by weight of octadecyl amine were added, the temperature being maintained at 200 F. for thirty minutes. Then 6.1 parts by weight of calcium oxide were edded and the reaction mixture was agitated at a temperature of 210 F. to 215 F. for at least one hour. The calcium sait thus formed was extracted with a volatile solvent, filtered and the solvent removed by distillation. The calcium salt prepared in accordance with this example was a solid having a milky appearance. The percent ash, as the oxide, was 5.0.

EXAMPLE V continued at 3 0 F. to 320 F. for one hour. The

reactants were then cooled to 000 F. and 38.0 parts by weight or octadecyi amine were added, the temperature being maintained at 200 F. 1'01: thirty minutes. After the addition or the amine, the reactants were dispersed in water and neutralized with six parts by weight of sodium hydroxide. The nickel salt was then prepared by reacting the sodium salt thus prepared with 212 parts by weight of an aqueous nickel nitrate solution. The nickel salt prepared in accordance with this example was a green tacky solid. The percent ash, as the oxide, was 8.0.

EXAMPLE VI In this example 34 parts by Weight of alphaterpinene were heated to a temperature from 310 F. to 320 F. Then 24.5 parts by weight of malelc anhydride were slowly added and the heating was continued at 310 F. to 320 F. for one hour. Ilia reactants were then cooled to 200 F. and 50 parts by weight of octadecyl amine were added, the temperature being maintained at 200 F. for thirty minutes. Then 6.6 parts by weight of aluminum hydroxide were added and the reaction mixture was agitated at a temperature of 210 F. to 215 F. for at least one hour. The aluminum salt thus formed was extracted with a volatile solvent, filtered and the solvent removed by distillation. The aluminum salt prepared in accordance with this example was a brown tacky solid. The percent ash, as the oxide, was 3.3.

EXAMPLE VII In this example 10 parts by weight of alphaterpinene were heated to a temperature from 310 F. to 320 F. 7.2 parts by weight of maleic anhydride were slowly added and the heating continued at 310 F. to 320 F. for one hour. The reactants were cooled to 200 F. and 20.5 parts by weight of a mixture of amines were added, the temperature being maintained at 200 F. for 30 minutes. The composition of the mixture of amines was 30 per cent hexadecyl amine, 25 per cent octadecyl amine and 45 per cent octadecenyl amine. Then, 6 parts by weight of calcium hydroxide mixed with one part by weight of water were added and the reaction mixture was agitated at a temperature of 210 F. to 215 F. for at least one hour. The calcium salt thus formed was extracted with a volatile solvent, filtered and the solvent removed by distillation.

The salts prepared in accordance with this invention are excellent addition agents for hydrocarbon lubricating oils. Concentrates can be readily prepared by extracting these salts with an oil in lieu of a solvent which can be distilled off. When the oil solution is filtered to remove any polymerized material, a valuable concentrate remains which may then be diluted down to the proportions desired in the final hydrocarbon oil lubricant compositions. However, in some instances, for example in the case of the aluminum salt, which is less soluble, it may be desirable to incorporate the salt directly into the mineral oil in the desired proportions. All types of hydrocarbon oils, including mineral oils, such as paraffinic, naphthenic, and mixed-base mineral oils,

can be employed.

As stated, my new addition agents are remarkably eflectlve in inhibiting rust and in improving cletergen-t properties of hydrocarbon lubricating oil compositions. For this purpose small amounts oi my new addition agents are generally sufficient. For example, the addition agents of the Gravity, API 28.4 Viscosity, SUS 100 F 464 Viscosity, SUS 210 F 61.7 Viscosity Index 98 Flash point, F 480 Pour point, F. Sulfur, percent 0.17 Carbon residue, percent 0.06 Neutralization No. 0.03

These compositions were tested in a standard Lauson engine for their ability to prevent ringsticking. This test consists in placing 2.1 lbs. of the composition in the crankcase of a single cylinder Lauson diesel engine. The engine is operated under a 3 H. P. load at 1850 R. P. M. maintaining a cooling jacket temperature of 300 R, an oil temperature of 225 F. and an airto-fuel ratio of 13:1. At the end of 24 hours operation under these conditions the engine is stopped, disassembled, and the piston is examined as to stuck rings and discoloration. If there are no stuck rings, the engine is reassembled, the oil charge is brought up to 2.1 lbs., and operation is continued for another 24-hour period. This procedure is repeated until one of the rings sticks or until a total of 216 operating hours has accrued. The piston varnish formation is compared with a set of prepared standards and given an Arbitrary Varnish Rating Value. The piston color is rated on this arbitrary scale which ranges from (no varnish formed) to 0 (very heavy varnish formation) representing increasing discoloration of the piston skirt. The data obtained in these tests on the following compositions is summarized below. Numbers indicate per cent I Although the test on Composition IV was stopped because of mechanical trouble, it will be seen from these data that the addition of relatively small proportions of the magnesium salt prepared in accordance with this invention to a typical crankcase lubricant effects an approximately fourfold increase in the time required for ring-sticking to occur in a diesel engine. Results of Lauson engine tests on other additives of this invention are given in the tables below. The salts used were magnesium, calcium and nickel salts prepared in accordance with Examples I, IV, and V respectively.

Table II Composition Nickel Salt (3.757 Magnesium Salt Base 011 (Same Length of by Wt. Based on (5.07 by Wt. gest, as m Table I) Oil) Based on Oil) ours 4 No. o. of No. of Piston Piston Piston Stuck Stuck Stuck Color Rm 5 Color Rings Color Rings 0. 0. 0. l freed. 1.

Table III Composition Calcium Salt (4.07 Base Oll (Same as h Wt. Based on Length of Test, Hours in Table I) y Oil) N o. of No. of 33 3? Stuck 82:3? Stuck Rings Rings 24 2+ 0 8 0. 48 0 1 5+ ltreed. 72 5+ Do. 5+ 0. 5 0. 4 1.

Engine trouble was encountered so that rings had to be freed. but the tests still show marked improvement particularly in piston color over the 50 by weight base oil.

In order to demonstrate the anti-rust propercomp0 Comw Comm Comm ties of the compositions prepared in accordance sitlonI smon II smonIII smon IV with this invention, an oil containing a small amount of the magnesium salt was subjected to Base ubri the test specified in the ASTM Standards on 1 9 M ffslffii s lillgorepar- 00 0 7 0 0 0 Petroleum Products and Lubricants, September edinExample 0.0, 3.0 6 0 6-0 1945, and designated as ASTM D-665-44T. In brief, the test consists in placing a 300 ml. sample Composition Length of I II III IV Test, Hours No of i No. 01 No. of No.01 Piston Piston Piston Piston Stuck Stuck Stuck Stuck Color Rings Color Rings Color Rings Color Rings of the oil or oil composition to be tested in a 1100 ml. beaker which is immersed in a constant temperature bath maintained at 140 F. The beaker is fitted with a cover provided with openi-ngs for a stainless steel motor-driven stirrer and for insertion of a standard steel test bar, inch in diameter and inches long, which has been very carefully cleaned and polished just prior to the test. The stirrer is started, and when the oil sample in the beaker reaches a steady temperat ture of 140 F. the test bar is inserted in the proper opening and hangs suspended from the beaker cover. After 30 minutes, 30 ml. of distilled water are added to the beaker. an irrin is continued for 48 hours, after which time the test bar is removed and examined for rust spots. In carrying out this test 0.05 per cent by weight on the oil of the magnesium salt prepared in accordance with Example I was used, The oil employed in the test was an aluminum chloridetreated paraffinic oil having a viscosity of 150 SUS at 100 F. A test was carried out on the base oil, and on the base oil having said magnesium salt incorporated therein. No rust formed on the test bar in my inhibited oil even after 4-8 hours. The test bar in the base oil showed signs of rust within four hours.

The above tests show the remarkable rustinhibitlng and detergent-conferring properties of the additives prepared in accordance with the instant invention. Hydrocarbon oil lubricant compositions containing my new addition agents are therefore suited for use where operating conditions are extremely severe, as in diesel. tank and truck engines, and in the lubrication of steam turbines. Moreover, the addition agents of the present invention cooperate efiectively with other additives. Other known addition agents which may be incorporated into lubricating compositions prepared in accordance with my invention are, for example, pour point depressants, extreme pressure agents, and the like. An oil containing a small amount of the addition agent of this invention in combination with a commercial oxidation corrosion inhibitor was tested in a Chevrolet engine. Both the piston varnish rating and the combined engine varnish and sludge rating were perfect, indicating that the detergent of the present invention does not appreciably affect the bearing corrosion value, but cooperates with the commercial corrosion inhibitor.

While I have shown in the examples the preparation of compounded lubricating oils, my invention is not limited thereto but comprises other hydrocarbon oil lubricant compositions containing my new addition agents such as greases and the like. Moreover, many modifications or variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof and, therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A lubricant composition comprising a major amount of a hydrocarbon lubricating oil, and a minor amount, sufiicient to confer improved detergent properties on the composition of a polyvalent metal salt of a monoamide of a dicarboxylic acid wherein the two N-substituents are selected from the group consisting of hydrogen, and alkyl and alkenyl radicals, at least one substituent being an organic radical of said group, and the total number of carbon atoms in the N- substituents is 8 to 22, and wherein said dicarboxylic acid is selected from the group consisting of unsubstituted and alkyl-substituted 2,5 endoethylene A cyciohexene 1,6 dicarboxylic acids, said alkyl-substituted dicarboxylic acids having not more than 4 alkyl groups each having not more than 6 carbon atoms.

.2. A lubr ant comp sition com risin a major amount of a hydrocarbon lubricating oil and a minor amount, sufficient to impart rust-inhibiting properties to the composition of a polyvalent metal salt of a monoamide of a dicarboxylic acid wherein the two N-substituents are selected from the group consisting of hydrogen, and alkyl and alkenyl radicals, at least one substituent being an organic radical of said group, and the total number of carbon atoms in the N-substituents is 8 to 22, and wherein said dicarboxylic acid is selected from the group consisting of unsubstituted and alkyl-substituted 2,5-endoethylene- A cyclohexcne 1,6 dicarboxylic acids, said alkyl-substituted dicarboxylic acids having not more than 4 alkyl groups each having not more than 6 carbon atoms.

3. A lubricant composition comprising a major amount of a hydrocarbon lubricating oil and 0.01

to 20 per cent by weight of said oil, of a polyvalent metal salt of a mono-amide of a dicarboxylic acid wherein the two N-substituents are selected from the group consisting of hydrogen, alkyl and alkenyl radicals, at least one substituent being an organic radical of said group, and the total number of carbon atoms in the N-substituents being 8 to 22, and wherein said dicarboxylic acid is selected from the group consisting of unsubstituted and alkyl-substituted 2,5- endoethylene A cyolohexene-Lfi dicarboxylic acids. said alkyl-substituted dicarboxylic acids having not more than 4 alkyl groups each having not more than 6 carbon atoms.

4. A lubricant composition comprising a major amount of a hydrocarbon lubricating oil and a minor amount, sufficient to impart rust-inhibiting properties to the composition of a polyvalent metal salt of a monoamide of a dicarboxylic acid wherein the two N-substituents are hydrogen and an alkyl radical containing 8 to 22 carbon atoms, and said dicarboxylic acid is selected from the group consisting of unsubstituted and alkyl-substituted 2,5-endoethylene-A -cyclohexene- 1,6- dicarboxylic acids having not more than 4 alkyl groups each having not more than 6 carbon atoms.

5. A lubricant composition as defined in claim 4 in which said N-substitutents are hydrogen and an octadecyl radical.

6. A lubricant composition as defined in claim 4 in which said N-substituents are hydrogen and a hexadecyl radical.

7. A lubricant composition comprising a major amount of a hydrocarbon lubricating oil and 0.01 to 20 per cent by weight of said oil of a polyvalent metal salt of a monoamide of 2,5-endoethylene 2 methyl 5 isopropyl A cyclohexene-LS-dicarboxylic acid wherein the two N- substituents are selected from the group consisting of hydrogen and alkyl and alkenyl radicals and contain 8 to 22 carbon atoms.

8. A lubricant composition as defined in claim '7 in which said N-substituents are hydrogen and an octadecyl radical.

9. A lubricant composition as defined in claim 7 in which said N-substituents are hydrogen and a hexadecyl radical.

10. The process which comprises condensing alphaterminene with maleic anhydride to form 2,5 endeothylene 2 methyl 5 isopr0py1-A -cyolohexene-1,6-dicarboxylic acid, re acting the resulting dicarboxylic acid under amidating conditions with an amine selected from the group consisting of primary and secondary alkyl and alkenyl amines having a total of from 8 to 22 carbon atoms to form the monoamide, and forming the polyvalent metal salt of the monoamide.

11. The process which comprises heating dipentene to rearrange the double bonds of said dipentene to a conjugated system, reacting the resulting isomer with maleic anhydride at an elevated temperature which is suflicientl high to start the reaction, reacting the resulting 2,5- endoethylene-Z-methyl 5 isopropyl-A -cyclohexane-1,6-dicarboxylic acid under amidating conditions with an amount adapted to form the monoamide of an amine selected from the group consisting of primary and secondary alkyl and alkenyl amines having a total of from 8 to 22 carbon atoms, and forming the polyvalent metal salt of the resulting monoamide.

12. The process which comprises heating one mol of dipentene to a temperature from about -a 280 F. to 375 F. to rearrange the double bonds to a conjugated system, reacting the resulting isomer at a temperature of about 140 to 375 F. with about one mol of maleic anhydride, reacting the product so formed, to form the monamide, with about one mol of an amine selected from the group consisting of primary and secondary amines wherein the N-substituents are selected from the group consisting of hydrogen and alkyl and alkenyl radicals and contain a total of 8 i to 22 carbon atoms, at a temperature from room temperature to about 250 F., and forming the polyvalent metal salt of the amide so formed. 13. A process in accordance with claim 12 in which the amine is octadecylamine.

14. A process in accordance with claim 12 in which the amine is hexadecylamine.

15. A polyvalent metal salt of a monoamide of a dicarboxylic acid wherein the two N-substituents are selected from the group consisting of hydrogen, and alkyl and alkenyl radicals, at least one substituent being an organic radical of said group, and the total number of carbon atoms in the N-substituents is 8 to 22, and wherein said dicarboxylic acid is selected from the group consisting of unsubstituted and alkyl-substituted 2,5- endoethylene-N -cyclohexene-lfi dicarboxylic acids, said alkyl-substituted dicarboxylic acids having not more than 4 alkyl groups each having not more than 6 carbon atoms.

16. A polyvalent metal salt as defined in claim 15 in which said N-substituents are hydrogen and an octadecyl radical, and said polyvalent metal is magnesium.

17. A polyvalent metal salt as defined in claim 15 in which said N-substituents are hydrogen and a hexadecyl radical, and said polyvalent metal is magnesium.

18. A polyvalent metal salt of a monoamide of 2,5 endoethylene-2-methyl-5-isopropyl-A -cyclohexene-1,6-dicarboxylic acid wherein the two N-substituents are selected from the group consisting of hydrogen and alkyl and alkenyl radicals and contain 8 to 22 carbon atoms.

19. A polyvalent metal salt as defined in claim 18 in which said N-substituents are hydrogen and an octadecyl radical.

20. A polyvalent metal salt as defined in claim 18 in which said N-substituents are hydrogen and a hexadecyI radical.

EDWARD MITCHELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,101,323 Salzberg Dec. '7, 1937 2,408,102 Smith et a1 Sept. 24, 1946 zap- 

1. A LUBRICANT COMPOSITION COMPRISING A MAJOR AMOUNT OF A HYDROCARBON LUBRICATING OIL, AND A MINOR AMOUNT, SUFFICIENT TO CONFER IMPROVED DETERGENT PROPERTIES ON THE COMPOSITION OF A POLYVALENT METAL SALT OF A MONOAMIDE OF A DICARBOXYLIC ACID WHEREIN THE TWO N-SUBSTITUENTS ARE SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ANDALKYL AND ALKENYL RADICALS, AT LEAST ONE SUBSTITUENT BEING AN ORGANIC RADICAL OF SAID GROUP AND THE TOTAL NUMBER OF CARBON ATOMS IN THE NSUBSTITUENTS IS 8 TO
 22. AND WHEREIN SAID DICARBOXYLIC ACID IS SELECTED FROM THE GROUP CONSISTING OF UNSUBSTITUTED AND ALKYL-SUBSTITUTED 2,5 - ENDOETHYLENE - $3:4 - CYCLOHEXENE - 1,6 - DICARBOXYLIC ACIDS, SAID ALKYL-SUBSTITUTED DICARBOXYLIC ACIDS HAVING NOT MORE THAN 4 ALKYL GROUPS EACH HAVING NOT MORE THAN 6 CARBON ATOMS. 